Add new function to filter fstab options

[elogind.git] / src / shared / fstab-util.c

diff --git a/src/shared/fstab-util.c b/src/shared/fstab-util.c
new file mode 100644 (file)
index 0000000..546c81b
--- /dev/null
+++ b/src/shared/fstab-util.c
@@ -0,0 +1,145 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2015 Zbigniew Jędrzejewski-Szmek
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include "fstab-util.h"
+#include "strv.h"
+#include "util.h"
+
+int fstab_filter_options(const char *opts, const char *names,
+                         const char **namefound, char **value, char **filtered) {
+        const char *name, *n = NULL, *x;
+        _cleanup_strv_free_ char **stor = NULL;
+        _cleanup_free_ char *v = NULL, **strv = NULL;
+
+        assert(names && *names);
+
+        if (!opts)
+                goto answer;
+
+        /* If !value and !filtered, this function is not allowed to fail. */
+
+        if (!filtered) {
+                const char *word, *state;
+                size_t l;
+
+                FOREACH_WORD_SEPARATOR(word, l, opts, ",", state)
+                        NULSTR_FOREACH(name, names) {
+                                if (l < strlen(name))
+                                        continue;
+                                if (!strneq(word, name, strlen(name)))
+                                        continue;
+
+                                /* we know that the string is NUL
+                                 * terminated, so *x is valid */
+                                x = word + strlen(name);
+                                if (IN_SET(*x, '\0', '=', ',')) {
+                                        n = name;
+                                        if (value) {
+                                                free(v);
+                                                if (IN_SET(*x, '\0', ','))
+                                                        v = NULL;
+                                                else {
+                                                        assert(*x == '=');
+                                                        x++;
+                                                        v = strndup(x, l - strlen(name) - 1);
+                                                        if (!v)
+                                                                return -ENOMEM;
+                                                }
+                                        }
+                                }
+                        }
+        } else {
+                char **t, **s;
+
+                stor = strv_split(opts, ",");
+                if (!stor)
+                        return -ENOMEM;
+                strv = memdup(stor, sizeof(char*) * (strv_length(stor) + 1));
+                if (!strv)
+                        return -ENOMEM;
+
+                for (s = t = strv; *s; s++) {
+                        NULSTR_FOREACH(name, names) {
+                                x = startswith(*s, name);
+                                if (x && IN_SET(*x, '\0', '='))
+                                        goto found;
+                        }
+
+                        *t = *s;
+                        t++;
+                        continue;
+                found:
+                        /* Keep the last occurence found */
+                        n = name;
+                        if (value) {
+                                free(v);
+                                if (*x == '\0')
+                                        v = NULL;
+                                else {
+                                        assert(*x == '=');
+                                        x++;
+                                        v = strdup(x);
+                                        if (!v)
+                                                return -ENOMEM;
+                                }
+                        }
+                }
+                *t = NULL;
+        }
+
+answer:
+        if (namefound)
+                *namefound = n;
+        if (filtered) {
+                char *f;
+
+                f = strv_join(strv, ",");
+                if (!f)
+                        return -ENOMEM;
+
+                *filtered = f;
+        }
+        if (value) {
+                *value = v;
+                v = NULL;
+        }
+
+        return !!n;
+}
+
+int fstab_find_pri(const char *options, int *ret) {
+        _cleanup_free_ char *opt = NULL;
+        int r;
+        unsigned pri;
+
+        assert(ret);
+
+        r = fstab_filter_options(options, "pri\0", NULL, &opt, NULL);
+        if (r <= 0)
+                return r;
+
+        r = safe_atou(opt, &pri);
+        if (r < 0)
+                return r;
+
+        *ret = (int) r;
+        return 1;
+}